


The Philosopher's Stone

by FantasticNumberNine



Series: John Watson and the Philosopher's Stone [9]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: AU, Crossover, Flying keys, Gen, Mirror of Erised, Potterlock, Three headed dogs, Trolls, devils snare, dumbledore vagueness, giant chessboards, gryffindor winning things, riddles requiring logic, trapdoors
Language: English
Status: Completed
Published: 2014-07-15
Updated: 2014-07-15
Packaged: 2018-02-09 00:14:18
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,549
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1961571
Author URL: https://archiveofourown.org/users/FantasticNumberNine/pseuds/FantasticNumberNine
Summary: <blockquote class="userstuff">
              <p>Exams are done and Dumbledore has left the school, leaving the stone unprotected. John takes it on himself to steal the stone first, and Greg and Mycroft can't let him go on his own.</p>
            </blockquote>





	The Philosopher's Stone

**Author's Note:**

> Apologies for the delay.
> 
> Borrowed several lines from Madame Rowling. And obviously the characters aren't mine.

"Well, that was far easier than I thought it would be," Mycroft had the gall to sound disappointed, talking about their exams they'd just finished.

"If you start going over history like you did potions, I'm feeding you to the giant squid." Greg flopped himself onto the grass beneath a willow tree close to the lake, and Mycroft sat beside him with more grace. "Smile, John, we've got a week before we find out how badly we've done so there's no need to worry yet."

John leaned against the tree and rubbed at his forehead, "My scar won't stop burning, it's never hurt this often before. I think it's a warning..."

"John, it is too hot for panic. And I agree with Mycroft, so long as Dumbledore's around we're safe. Besides, Hagrid would never betray Dumbledore to anyone."

John frowned, nodding, but Mycroft shot to his feet with stunning speed.

"Holmes..." Greg grumbled, he'd been leaning against him and only just managed not to eat tree roots and grass.

"No, he wouldn't. At least not knowingly--"

"Oh not you too--"

John met Mycroft's eyes and understood instantly: "The dragon egg."

"I'm not following, what's Norbert got to do with the stone?"

Mycroft sighed, "Isn't it an interesting _coincidence_ , that a mysterious stranger happens to have a _dragon egg_ to gamble in a game of chance with _Hagrid_?"

"You don't believe in coincidence--oh!" Greg jumped to his feet and the trio was off, running to Hagrid's.

After, when John had thrown all caution to the wind and they'd been summarily dismissed by McGonagall, John turned to his friends.

"It's tonight. Snape's going after the stone tonight. He knows everything and he's even gotten Dumbledore out of the way. He sent that note, I bet the Ministry has a real shock when Dumbledore shows up."

"But, what can--"

Mycroft cleared his throat loudly, eyes wide. John and Greg spun around.

"Good afternoon." Snape was standing there, smiling an odd, twisted little smile. "You shouldn't be inside on a day like this."

"We..." John had no idea what to say.

"You want to be more careful, hanging around like this. People will think you're up to something. And Gryffindor really can't afford to lose any more points, can they?"

John clenched his fists.

"Be warned, Watson--any more nighttime wanderings and I will personally make sure you are expelled."

Back in the common room, John stood between his friends--a bit pasty, but a determined light in his eyes. "I'm going after the stone. Tonight."

"You're mental!"

"After what McGonagall and Snape said? You'll be expelled, John!" 

"SO WHAT?" John exploded. "Don't you understand? If Snape gets the stone to Voldemort, he'll be back and there won't _be_ any Hogwarts to get expelled from! I've heard what he did before, and Gryffindor winning the house cup isn't going to stop him killing me, or you, or your families, or anyone else! So what if I get caught? They'll send me back to the Dursley's and he'll kill me that much later because I'm never joining him, not ever! I am going after the stone tonight and nothing either of you can say will stop me! If you'll remember, Voldemort killed my parents!"

There was a moment of silence before Mycroft spoke in a quiet voice, "You're right, John."

"I'm going to use the invisibility cloak."

Greg spoke up, "Will it cover all three of us?"

John blinked at him. "Sorry?"

"Come off it, did you really think we'd let you go alone?"

"Don't be absurd, John," Mycroft added briskly. "How were you intending to get the stone without me--us?"

Greg rolled his eyes.

"You'll both be expelled with me if we get caught--"

"I very much doubt that," Mycroft had rediscovered his smug smirk. "Professor Flitwick informed me secretly that I scored one hundred and twelve percent on his exam. They won't throw me out after that."

The boys sat anxiously through dinner--or at least, John and Greg did, Mycroft seemed to have accepted what they were intending to do and was distinctly unperturbed--and then sat waiting for their common room to empty, Mycroft with a book while John and Greg absentmindedly played what could loosely be called a game of chess.

When Lee Jordan finally left, John went up to their dorm to retrieve his invisibility cloak and remembered Hagrid's present from Christmas--the flute was a relief, he wasn't too keen on singing.

"You can't go out, you'll get Gryffindor in even more trouble. I won't let you do it." Molly stood in front of the portrait hole, clearly desperate. "I... I'll fight you!"

"Molly," Greg growled. "Get out of the way and don't be an idiot--"

"Don't you call me an idiot, Greg! You shouldn't be breaking any more rules!" said Molly. "You were the one who told me to stand up to people!"

Mycroft stepped forward, "Molly, I am sorry to have to do this: _Petrificus Totalus_!"

Molly fell over, stiff as a board, and Mycroft crouched down to turn her over.

"What did you do to her?" John whispered.

"It's the full Body-Bind."

A while later they were outside the third floor corridor, the door was ajar.

"Snape's already got past Fluffy--"

"Ridiculous name for a Cerberus..." Mycroft muttered.

Greg elbowed him.

John edged the door open and put the flute to his lips. The dog was already asleep, but restless, and calmed as John played. 

Greg gritted his teeth and stepped gingerly over the dog's legs and pulled open the trapdoor, peering into the darkness below. "Want to go first, Mycroft?"

"Very funny."

John waved for Greg's attention and pointed at himself before handing the flute to Mycroft. 

"I'm going first."

John landed with a muffled thump on something surprisingly soft, a plant, he decided.

"It's alright, you can jump! There's a sort of plant that'll break your fall!"

Greg jumped first, landing to John's right. "Come on Mycroft!"

The music stopped and moments later Mycroft was on John's left.

"That wasn't so bad--lucky this plant's here, really."

" _Lucky_?" Mycroft shrieked, struggling to his feet. "Look at you both!"

Mycroft managed to get himself safely to the wall, but John and Greg were already ensnared, bound tightly without their notice by the snake-like vines.

"What do we do?" John and Greg fought against the plant, but the more they struggled, the tighter it held them.

"Stop moving--it's a Devil's Snare!"

Greg growled. "Oh, I'm so glad we know what it's called, that's a great help!"

"Shut up, Gregory! Devil's Snare... It grows in the dark, it prefers the damp of--"

"Then light a fire!" John choked out.

"Yes--of course--but there's no wood!" Mycroft was wide eyed and panicking.

"HAVE YOU COMPLETELY LOST IT?" Greg bellowed. "YOU'RE A WIZARD, AREN'T YOU?"

"Right. Of course." Mycroft spluttered, whipping out his wand and sending a jet of the same fire he'd used on Snape at the plant.

Wiping sweat off his face, John joined Mycroft by the wall. "Lucky you remembered about the Devil's Snare."

"Yeah, and lucky John doesn't lose his head in a crisis--'there's no wood', _honestly_."

Down a passageway, the boys heard a soft rustling and odd clinking ahead of them. At the end of the passage, the boys walked into a brightly lit chamber with a high and arched ceiling. Hundreds of birds, all jewel-bright, fluttered around the room, and a heavy door waited for them on the opposite side.

The door was locked, and even Mycroft couldn't open it with his Alohomora Charm.

"Now what?"

"The birds... They aren't just here to decorate, I believe." Mycroft murmured, staring at the glittering birds overhead.

 _Glittering_? 

"They're not birds!" John exclaimed. "They're keys! Flying keys! Which means--broomsticks! We've got to catch the right key!"

"There are, of course, only several _hundred_ of them."

Greg was examining the lock, "It'll probably be a big, old-fashioned one--and silver, like the handle."

The three boys take to the air, but in the end, John isn't the youngest Seeker in a century for nothing and he lands with the key in hand.

The next chamber is too dark to see in, and they step through cautiously. Light flooded the room and Greg and Mycroft gazed longingly at the sight before them. 

"What do we do?" John whispered.

"It's obvious, isn't it?" Greg answered. "We have to play our way across the room."

"We'll have to be chessmen," Mycroft added, observing the board with curious fascination.

Greg adopted a look of intense concentration before glancing at Mycroft. Finally, he said, "Right, don't be offended or anything, Mycroft, but--"

"Oh, please spare me. You are the better chess player, this whole year stands as evidence." Mycroft was obviously annoyed, but John could see it was more with himself than with Greg.

"Right..." Greg looked back at the board. "John, you'll replace that bishop, and Mycroft, you go next to him instead of the castle."

"And you?"

"I'm going to be a knight."

And the game began. Greg directed the black pieces and John, despite the adrenaline coursing through him, was a bit nervous. What happened if they lost?

"John, four squares diagonally to the right."

And then their other knight was taken by the white queen and the three of them went a bit green. Greg looked shaken.

"Mycroft, the bishop..."

The pieces were piling up along the wall, white and black alike. They needed to win, but Greg wouldn't risk his friends.

"Almost there... I need..." He watched the white queen turn her blank face towards him. "Yes... It's the only way... I've got to be taken."

"What? No!" John shouted even as Mycroft saw the truth of it.

"That's chess, John!" Greg snapped. "Sacrifices have to be made! If she takes me, you'll be free to checkmate the king!"

"He's right, John."

"But--" 

"Do you want to stop Snape or not?"

In the end, Mycroft had to drag John through the door. 

"But what if he's--"

"He'll be alright. He has a thick head."

They reached the next room and Mycroft pushed open the door only to yank it shut again, both boys coughing the disgusting smell out of their lungs. 

"At least we don't have to fight that one." John reached for the door, "Come on, we'll take it at a run."

Past the unconscious troll was a smaller room with only one long table and seven differently shaped bottles lined up in the center. As they stepped over the threshold, purple fire sprang up in the doorway behind them and black flames in the doorway ahead of them.

"Snape's?"

"Snape's." Mycroft walked to the table and picked up the scroll lying beside the bottles and John stood beside him to read it.

He was a bit surprised at Mycroft's happy sigh and appreciative smile. 

" _Magnificent_." Mycroft began pacing up and down the table, peering closely at the bottles. 

"Sorry?"

"This isn't magic, John, it's logic. A puzzle. A failing common among wizards, they haven't an ounce of logic and would therefore be stuck here forever."

"Right. And why are you smiling?"

Mycroft stopped his perusal and turned to John, "Everything we need is here in this paper. Seven bottles: three are poison; two are wine; one will get us through the black fire, and the other through the purple."

"And you know which is which, do you?"

Mycroft smiled, pointing at the smallest bottle. "That one will take us through to the stone."

John looked at the tiny bottle, "There's not enough for both of us in there."

Mycroft's smile faded.

"Which one will take you back through the purple flames?"

Mycroft pointed at the slightly round bottle at the right end.

"John..."

"Go back and get Greg, use the brooms and get out. Go to the owlery--"

"John, what if He-Who-Must-Not-Be-Named is with him?"

John pointed at his scar, "I was lucky once before, maybe it'll hold out."

Mycroft picked up his bottle, and then set it back down, pulling a surprised John into a tight hug.

" _Mycroft!_ "

"John, you are a great wizard. You are aware of that."

"Not as good as you," John muttered, rather embarrassed as Mycroft let him go.

Mycroft raised one eyebrow. "Knowledge and cleverness are all I've ever known, John. Friendship, courage, _you've_ been teaching me those."

"Greg, too."

Mycroft sighed. "Do be careful, John."

After Mycroft disappeared through the purple flames, John took a deep breath and faced the other door. He swallowed the mouthful of his potion in one gulp and walked through the black fire into the final chamber.

It wasn't Snape waiting on the other side.

" _Quirrell_?"

Quirrell smiled calmly. "I wondered whether I'd be meeting you here, Watson."

"But... Snape--"

"Yes, Severus does seem the type, doesn't he? Who would suspect p-p-poor st-stuttering P-Professor Quirrell, with him swooping around like an overgrown bat?"

John was outraged. It couldn't be true.

"Snape tried to _kill me_!"

" _I_ tried to kill you, you fool. Your friend Mr. Holmes accidentally knocked me over in his rush to set fire to Snape. Another few seconds and I'd have had you off your broom--I'd have been quicker if Snape hadn't been muttering a counter-curse."

"Snape tried to save me?"

"Much good it's done, after all, I'll be killing you tonight." 

With a snap of Quirrell's fingers, ropes came out of thin air and wrapped themselves tightly around John.

"Wait quietly, Watson, I need to examine this very interesting mirror."

Which was when John noticed that behind his professor, stood the Mirror of Erised. A tad vainly, John attempted to distract Quirrell from the mirror, but Quirrell was staring at it too hungrily.

"I see the stone... I'm presenting it to my master..."

John struggled against the ropes.

"Is the stone _inside_ the mirror? Am I meant to break it?"

John's mind was racing--if could look into the mirror, he knew what he'd see, because above everything else, he _needed_ to find the stone before Quirrell.

"Help me, Master!"

To John's horror, a voice answered, a voice that seemed to come from Quirrell himself.

"Use the boy... Use the boy..."

Quirrel rounded on John.

"Yes--Watson--come here."

With a clap of his hands, John was free.

"Come here," Quirrell repeated. "Look in the Mirror and tell me what you see."

John had never been very good at lying, but he knew that he'd have to try now.

He stepped in front of the mirror and saw his reflection, pale and terrified, before his face morphed into a smirk. His reflection put a hand in his pocket and withdrew a blood-red stone and, winking, put it back. John stifled a gasp as something heavy dropped into his real pocket.

"Well?" Quirrell demanded. "What do you see?"

John started. 

"I... I'm shaking hands with Dumbledore... We--Gryffindor, we've won the House Cup, I won the cup for Gryffindor, and quidditch too!"

Quirrell cursed and shoved him away. John considered making his escape, but the high voice spoke once more.

"He lies... He lies..."

"Watson! Tell the truth!" Quirrell shouted. "What did you see?"

"Let me speak to him... Face to face..."

"Master, you are not strong enough!"

"I have strength enough... For this..."

John stood rooted to the spot, as frozen as they'd left Molly in Gryffindor Tower. He watched as Quirrell slowly unwound his turban and turned slowly.

Where there ought to have been the back of Quirrell's head, was another face. A terrible, horrible, face, chalk white with malicious red eyes and slits for nostrils, like a snake.

"John Watson..." It whispered.

John wanted to take a step, or fifty, back, but his legs wouldn't move.

"See what I have become? I have form only when I can share another's body... Unicorn blood has strengthened me... And once I have the Elixir of Life, I will be able to create a body of my own... Now... Why don't you give me that stone in your pocket?"

He knew. He knew John had the stone. 

"Save your own life... Join me... Or you'll meet the same end as your parents... They died begging me for mercy..."

"LIAR!" John shouted, stumbling backwards.

"Bravery... Yes... Your parents were brave... I killed your father first and he put up a courageous fight... But your mother needn't have died... She was trying to protect you... Now... Give me the stone, unless you want her to have died in vain."

"NEVER!"

Everything happened quickly after that. John tried to run for the door, but Quirrell grabbed hold of him and a burning pain seared through John's scar. When it faded, John saw what had happened to Quirrell's hand and didn't stop to think. He leapt on the man, holding his head between his hands as the pain came back, worse than before, and Quirrell's screams filled the air.

Somewhere, he heard someone call his name. Someone pry him off of Quirrell. Someone hold him. But the blackness was stronger, and he fell. Down... Down... Down...

\--------------------

John woke in the Hospital Wing three days later to find Professor Dumbledore waiting beside his bed in a comfortable looking chair.

"I feared I might be too late."

"You nearly were, I couldn't have kept him off the stone much longer--"

"My dear boy, not the stone, _you_! What happened nearly killed you, for one terrible moment I was afraid it had. The stone itself has been destroyed."

John was certain Mycroft would be outraged at Dumbledore's and Flamel's reasoning, but another thought came to him.

"Voldemort's going to find another way to come back, isn't he? He's not really gone."

"No, John, he has not. He is still out there somewhere."

He sighed. 

"Sir? Voldemort said he only killed my mum because she tried to stop him killing me, but... Why did he want to kill me in the first place?"

"Alas, what you ask, I cannot tell you. Not today. Not now. You will know one day, but for now I ask that you put it from your mind, John. When you are older, when you are ready, you will know."

John knew better than to argue, but he was upset by the lack of answer.

"Right. Can you tell me why Quirrell couldn't touch me?"

"Your mother died to save you. If there is one thing Voldemort cannot understand, it is love. He didn't realize that love as powerful as your mother's for you leaves it's own mark. Not a scar, no visible sign... To have been loved so deeply, even though the person who loved us is gone, will give us some protection for ever."

John clenched his hands around his sheets, fighting back the overwhelming sensation he was feeling. He wouldn't cry.

"My invisibility cloak--do you know who sent it to me?"

Madame Pomfrey was a very kind woman. She was also very strict. It took a great deal of pleading, but Greg and Mycroft were granted five minutes visitation.

John was right, Mycroft was scandalized upon hearing of the stone's destruction. Greg announced that Slytherin had won the house cup, and Ravenclaw had beaten Gryffindor in the final quidditch match without John. Then they were sent away.

The next evening, before he was released to attend the feast, Hagrid came to see him, and left him a photo album full of wizarding photographs of his parents.

The great hall was decorated in Slytherin colours, at least for the moment. Dumbledore stood to announce the points, and then recent events were needing to be accounted for.

"To Mr. Gregory Lestrade, for the best-played game of chess Hogwarts has seen in many years, fifty points."

There were loud cheers at the Gryffindor table before Dumbledore spoke again.

"Second, to Mr. Mycroft Holmes, for the use of cool logic in the face of fire, fifty points."

Mycroft was a bit red as the Gryffindors reacted, they were up one hundred points!

"And to Mr. John Watson... For pure nerve and outstanding courage, sixty points."

The uproar was deafening, as those who could do maths while shouting themselves hoarse knew that Gryffindor was now tied with Slytherin.

"There are all kinds of courage. It takes a great deal of courage to stand up to our enemies, but just as much to stand up to our friends. I therefore award ten points to Miss Molly Hooper."

The feast was the best John had ever had--Greg took great delight in pointing out Moriarty's stunned and horrified face. Molly was showered with attention, and Mycroft was rolling his eyes at the noise by the end of it.

Exam results arrived, both John and Greg were pleased to find that they had passed with flying colors in most of their classes. Mycroft, unsurprisingly, was first in their year.

"You'll have to come stay at mine this summer, both of you--I'll send an owl." Greg said as they got off the train.

"Thanks," John said. "I'll need something to look forward to."

A lot of students called goodbyes to John as they made their way to the gateway.

"Still famous," Greg grinned.

"Not where I'm going, I promise you."

He, Greg, and Mycroft passed throughout the gateway together.

**Author's Note:**

> There's that done. :)


End file.
